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per-packet vs mls ip cef load-sharing full

What is the difference between ip load-sharing per-packet vs mls ip cef load-sharing full ? I have two wan links and we we want to utilize both link at all time. Thanks



Re: per-packet vs mls ip cef load-sharing full


CEF uses a hash algorithm to allow for load sharing. This hash algorithm will per default use destination IP to decide, where to send a packet.

The net result is, that all traffic to a specific destination will go through one link. Thus you might encounter situations, where one link is utilized heavily and the other is nearly idle.

"mls ip cef load-sharing full" will use a different hash including TCP/UDP port numbers. Thus each session will go through one link, but traffic to one server IP f.e. will be more evenly distributed. Still the order of packets for a single session is assured.

"ip load-sharing per-packet" will do load sharing on a per packet basis. This will give you the most even load distribution on your two links. The drawback is, however, that packets might be reordered because of different transmission times on both pathes. This is f.e. negative for voip and also might impact TCP throughput (the receiving system needs to reorder TCP segments received in the wrong order).

Hope this helps! Please rate all posts.

Regards, Martin

Community Member

Re: per-packet vs mls ip cef load-sharing full

Thanks a lot Martin.

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